JPS5962480A - Underwater storage tank for crude oil, etc. - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION 1. The present invention relates to an underwater storage tank for crude oil, etc.

Conventionally, various methods have been proposed for storing crude oil, etc., in addition to normal above-ground tanks, offshore storage using tankers, and terrestrial storage. It was not possible to put it into service and required enormous maintenance and management costs.On the other hand, stockpiling in underground tanks was expensive and unsuitable for Japan, where the bedrock is weak, and both methods had problems such as the difficulty of implementing safety measures against electrostatic fires. Submerged storage tanks have also been proposed, but in many cases a portion of the tank protrudes above the sea, which obstructs ship navigation and poses a safety problem.

The present invention was made in view of the above-mentioned situation, and its purpose is to effectively utilize the ocean without interfering with maritime navigation by installing storage tanks completely submerged on the seabed, etc. To provide an underwater storage tank for crude oil, etc., which can be used, is safe without fear of marine pollution, and has low construction costs and subsequent maintenance costs.

2- Hereinafter, one embodiment of the present invention will be described with reference to the drawings.
In the figure, 1 is a group of tanks on the ground, which is connected to a group of 3 storage tanks sunk on the seabed via a pipeline 2.2', and a guard block G protects the 3rd tank from being affected by waves, etc. protected.

In the example shown in FIG. 2, the storage tank 3 has a dual structure of inside and outside, consisting of a bowl-shaped internal tank 4 and an external tank 5, but the external tank 5 is eliminated and the internal tank 4 is constructed.
Sometimes it consists of only

In the illustrated example, the inner and outer tanks 4 and 5 are tank blocks 4a each made of a concrete pipe.

5a, 5b, . . . are laminated with seal packings 6 interposed therebetween, and the upper and lower blocks are fixed by embedded bolts (not shown). Each tank block has a well-balanced water pressure inside and outside the tank, so it can be removed by making the frame thinner.

The lowermost tank blocks 4a and 5a are each provided with a plurality of leg parts 7 at appropriate intervals in the lower half thereof, and the leg parts 7
, 7, an opening 8 is formed between them.

Reference numeral 9 denotes a concrete foundation, on which the legs 7 of the lowest tank blocks 4a, 5a are fixed so as to be half submerged, and on the upper outer periphery of the foundation 9 there is an outflow prevention wall 10 for the filled filtration layer 11. has been extended.

The filled filtration layer 11 is formed as a sand filtration layer in the illustrated example, and is filled and arranged so as to completely fill the openings 8 at the bottoms of the inner and outer tanks 4 and 5.

On the other hand, the uppermost tank blocks 4e and 5e are respectively lids, and a pipeline 12 for supplying and discharging crude oil, etc. is connected to the block 4e, and a pipeline 13 for detecting leakage of oil, etc. is connected to the block 5e. has been done. In addition, the pipeline 12 may be directly connected to the internal tank 4 as shown by a two-dot chain line 12' in order to reduce the number of sealing parts with the tank and easily prevent oil leakage. These pipelines 12 and 13 correspond to the pipelines 2 and 2', respectively.
Connect along or branch to these. 14
is a partition plate, which has a specific gravity between that of seawater and oil, and is mounted so as to be able to rise and fall along the inner wall of the internal tank 4, thereby preventing sludge, etc. in the heavy oil from passing through the filled filtration layer 11. Block it and prevent it from leaking outside.

1. To construct the storage tank 3 on the seabed, the lowermost tank blocks 4a and 5a are integrally molded with the foundation 9 on land or at sea, and then lifted to the seabed by a heavy lifting machine (not shown). After the tank blocks 4b..., 5b... are sequentially sunk in the same manner, the storage tank 2 is fixed with a wire 16° anchor bolt 17 to prevent the tank from floating up. Note that the lowermost tank blocks 4a and 5a may be directly fixed to bedrock such as the seabed.

In the above configuration, among the storage tanks 2, the external tank 4.
5 is initially filled with seawater, but when crude oil O is injected into the internal tank 4 from the pipeline 12, the crude oil floats to the surface due to the difference in specific gravity with the seawater and is contained in the tank, and the seawater W flows into the filled filtration layer. 11, the opening 8, and the filled filtration layer 11 to be discharged to the outside of the external tank 5 as indicated by the arrow P. internal tank 4
When pumping up crude oil from the tank, seawater flows into the tank 5-14= in the opposite manner to the above.

In this way, foreign matter is filtered out by the filled filtration layer 11 when the seawater flows into and discharges from the internal tank 4, so that the seawater is not contaminated by crude oil, and the crude oil is not contaminated by seawater. Furthermore, since the partition plate 14 is interposed at the interface between the crude oil and seawater, the sludge in the crude oil does not settle and contaminate and block the filled filtration layer 11, thereby preventing the crude oil from flowing out of the tank. It is prevented. If the crude oil contaminates the filled filtration layer 11 and flows out from the internal tank 4, it will float up between the inner and outer tanks 4.5 as indicated by the arrow P' and accumulate in the upper part of the pipeline. By regularly sampling from 13, the presence or absence of contamination can be quickly determined.

The above is a filtration layer 11 filled at the bottom of the inner and outer tanks 4.5.
We explained an example of filling sand in both tanks 4 and 4.
．． The inside of the tank 4.5 is filled with sand, and the space between the external tank 5 and the outflow prevention wall 10 is filled with an oil absorbent material such as polypropylene, or vice versa, the inside of both tanks 4.5 is filled with oil absorbent material. By filling the outer periphery with sand, contamination by oil can be more reliably prevented. Then, the oil adsorbent is placed in the external tank 5.
If it is filled around the area, it can be replaced easily.

In addition, an example has been described in which the external tank 4.5 of the storage tank 2 is constructed by stacking divided concrete tank blocks, but not only concrete blocks but also metal materials such as non-steel steel can be used. can be used.

Furthermore, the storage tank 2 is a system that takes advantage of the difference in specific gravity between crude oil, etc. and water, and the balance of water pressure inside and outside the tank. It is also possible to install it in

Since the present invention is as described in 1., it has the following effects.

(1) Since the tank is installed on the seabed, navigation on the sea becomes possible, and water bodies such as the ocean can be used effectively. or,
It is extremely safe as there is no risk of electrostatic fire.

7- (2) Seawater is introduced into and discharged from the tank through a filtering material such as sand on the seabed, so there is a risk that the seawater will be filtered and contaminate the oil inside the tank or, conversely, the seawater outside. It can be installed in a wide range of areas because it does not cause any environmental changes.

(3) Oil leaks can be detected quickly by making the storage tank have a double structure inside and outside.

(4) This type of submersible tank generally has a well-balanced water pressure inside and outside the tank, so the frame can be made thin, and material and construction costs are low.

(5) In addition, the tank can be made of concrete blocks, non-steel, etc., and the desired material and construction method can be selected, such as underwater or offshore assembly.

(6) Contaminated filter media can be replaced.

(7) If the tank group is to be discarded in the future, it would be best to reuse it as a huge artificial fish reef.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is an explanatory view of a storage tank sunk on the seabed, and FIG. 2 is an enlarged sectional view with a part of the storage tank cut away. 3... Storage tank, 4... Internal tank, 5... External tank, 8... Opening, 11... Filling filtration layer, 1
．． 2.13... Pipeline patent applicant Tokyu Construction Co., Ltd. 9-

Claims (2)

[Claims] (1) A tank with an opening at the bottom is installed submerged on the seabed, etc., and a pipeline for crude oil, etc. is installed in the internal tank to communicate with the above-ground part, and a filled filtration layer is installed facing the opening. An underwater storage tank for petroleum, etc., characterized in that, when crude oil, etc. is supplied to the internal tank, seawater, etc. flows into or is discharged from the internal tank through the filled filtration layer. (2) A tank with a double structure, inside and outside, with an opening at the bottom is installed submerged on the seabed, etc., and a pipeline for crude oil, etc. is installed in the internal tank to communicate with the above-ground part, and the opening is connected to the tank. 1. An underwater stockpiling tank for petroleum, etc., characterized in that a filled filtration layer is provided facing the inner tank, and seawater, etc. flows into or is discharged from the internal tank through the filled filtration layer when crude oil, etc. is supplied to the internal tank.